In these years, increase in skin diseases such as melanoma (melanocarcinoma) due to aging society and ozone depletion is a problem. For diagnosing such skin diseases, a device called dermoscope for viewing the pigment distribution and/or color of the inner skin part is utilized. For example, the dermoscope disclosed in Patent Literature 1: U.S. Pat. No. 7,006,223 is provided with a diode in each of different polarizing filters and can be switched between a state enabling observation of the skin surface and a state enabling observation of the inner skin part by switching the diode to emit light.